The rebuke comes as Sierra Club executive director Michael Burne thanked volunteers and staff at the Sierra Club’s campus in Washington DC last week for helping to “retire” or “repurpose” 187 US coal plants since the Beyond Coal campaign was launched in 2011.

The American Coal Council trade association’s Jason Hayes told CNSNews.com: “So the Sierra Club and Bloomberg were effectively bragging today about their collective ability to put 23,200 American miners out of work.

“One wonders if the Sierra Club is going to put any of Bloomberg’s multimillion dollar gifts to work helping these miners and families get retrained, or to help them pay their bills,” Hayes said.

“Or, will they continue to enjoy their six (or more) figure salaries and comfortable homes while they continue their campaigns to put more American miners out of work and shut down America’s industry?”

The UMWA said Bloomberg’s additional donation provided yet more ammunition for an effort that “has, and apparently will continue to put the lives, health and well-being of hundreds of thousands at risk in Appalachia and elsewhere”.

“By shutting down coal-fired power, this campaign is making it ever more difficult for those working in coal mines to keep their jobs, meaning not just a loss of income but also a loss of family health care and other benefits working coal miners earn,” the union’s president Cecil Roberts said.

“This campaign puts at direct risk the pensions and health care of more than 100,000 retired coal miners, their widows and dependents.

“This campaign puts at direct risk the ability of communities to support critical services like first responders, schools, and other needs of coalfield residents throughout Appalachia, the Midwest and other coal-producing areas of the United States.”

He said that Bloomberg and Brune could “spout all the happy talk they want” about the potential health benefits of their action, but “the fact is that they are putting the health and well-being of tens of thousands of children, families and seniors at serious risk”.

“I note that in their press release announcing this latest action, Mr Bloomberg and Mr Brune don’t once mention the people who will be most immediately affected by their actions: Those who live and work in Appalachia and the other American coalfield communities in the Midwest and western US,” Roberts said.

“We may be invisible from the skyscrapers of New York and the mountains of California, but we are here nonetheless. We have long, sad experience with powerful elites dictating what we do and how we live, but we have also learned to fight back. And that’s exactly what we’re going to do.”